1. Field of the Invention
The present invention relates to an organic electroluminescent device (organic EL device) and a display apparatus. In particular, the present invention relates to an organic electroluminescent device and a display apparatus that include an electron transport layer containing a nitrogen-containing heterocyclic derivative.
2. Description of the Related Art
Organic electroluminescent devices (organic EL devices) that use electroluminescence (hereinafter abbreviated as EL) of organic materials include an anode, a cathode, and an organic layer including a light-emitting layer and disposed between the anode and the cathode, and are attracting attention as light-emitting devices that can emit light with high luminance by a low-voltage direct current drive.
In organic electroluminescent devices having such a structure, various studies have been made on the layer structure between the anode and the cathode and configurations of materials for respective layers in order to improve luminous efficiency and lifetime characteristics. For example, a configuration has been proposed in which a dibenzimidazole derivative is used as a material for an electron injection layer and an electron transport layer that are provided between a light-emitting layer and a cathode (refer to Japanese Unexamined Patent Application Publication (Translation of PCT Application) Nos. 2008-521243 and 2008-521244).